Dual punch assembly for consolidating delay and fuse combustible material



Sept. 2, 1969 B H. SMITH 3. .311

DUAL PUNCH ASSEMBLY FOR CONSOLIDATING DELAY AND FUSE COMBUSTIBLEMATERIAL Filed April 12. 1968 5 $heets-$haet 1 mvmworc Boyd H. SmithSept. 2, 1969 a. H. SMITH 3,464,311

DUAL PUNCH ASSEMBLY FOR CONSOLIDATING DELAY AND FUSE COMBUSTIBLEMATERIAL 5 Sheets-Sheet 2 Filed April 12. 1968 Fig.3

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INVENTOR. B oyd H.S mith BY 7 Sept. 2, 1969 a. H. SMITH 3,464,311

7 DUAL PUNCH ASSEMBLY FOR CONSOLIDATING DELAY AND FUSE COMBUSTIBLEMATERIAL Filed April 12 1968 5 Sheets-Sheet 5 Fig.5 INVENTOR. B o yd H.8 mi t h United States Patent 3,464,311 DUAL PUNCH ASSEMBLY FORCONSOLIDATING DELAY AND FUSE COMBUSTIBLE MATERIAL Boyd H. Smith,Marshall, Tex., assignor to Thiokol Chemical Corporation, Bristol, Pa.,a corporation of Delaware Filed Apr. 12, 1968, Ser. No. 721,027 Int. Cl.F42b 33/00, 33/02 US. Cl. 86-1 4 Claims ABSTRACT OF THE DISCLOSURE Apunch assembly adaptable to be driven by a punch press for consolidatingcombustible material in powder train delay fuses and the like isdisclosed. The punch assembly includes a housing with a pivot barswivelably mounted therein which contacts a pair of free floatingpunches. The punches thus transmit predetermined compacting, orconsolidating loads to the material in the delay or fuse.

SPECIFICATION This invention relates to loose material compacting, orconsolidation devices and to devices of that character which areadaptable for use on, or to be driven by a punch press which producesthe forces required for consolidating. More particularly, this inventionconcerns a punch assembly wherein a pair of free floating punches arecontacted by a swivelable body so mounted in a housing that a loadproduced by a punch press is distributed equally on the punches. By thismeans, delay and fuse assemblies having powdered combustible materialloosely contained within them, which is to be ignited, can be prepared.

Such delay and fuse assemblies are very desirable in devices such asaerial flares, bombs and similar objects which depend upon a predictabletime delay before a main explosive or illuminating charge is to beinitiated. For example, certain illuminating flares, particularly thoseadapted to be launched by artillery field pieces such as the 155millimeter howitzer, are dimensionally and lballistically matched withthe regular 155 mm. explosive round, i.e., the flare or illuminatinground can be fired from the artillery piece without changing thepropelling charge and with little or no change in gun position andsetting in the field.

In the usual instance, flares of the above type have a forward noseportion which contains a mechanical timer, or time fuse adapted toignite an initial, or primary expelling charge. This ignited chargecreates pressure gas which causes the release of a first, or drogue typeof parachute and simultaneously ignites a combustible delay assembly,which if properly compacted, or consolidated in manufacture, will burnfor an accurately predictable time period. At the end of the delayburning time, a secondary expelling charge is ignited which createspressurizing gas to release the main flare body containing combustibleilluminant, and ignites said illuminant. The main flare body usuallycontains a cannister and is attached to a main parachute which permits aslow descent to illuminate a preselected target area.

It is, however, quite obvious that ignition of the flare shoulddesirably not occur, that is, should be delayed, until the flare is in aposition over a preselected site, or target area to be illuminated. Inpractice it has been found that a delay or fuse assembly comprising apair of parallel columns, or delay trains of carefully compacted, orconsolidated combustible material, disposed within preferably a metalbody provides proper time delay, in flight, between the primaryexpelling charge and the secondary expelling charge to achieve theilluminating objectives 3,464,31 1 Patented Sept. 2, 1969 ice abovedescribed. It should also be here noted that while either one of the twodelay columns or trains will accomplish the desired result, it is usualand prudent, to provide a second, identical delay to increasereliability.

In practice delay trains with which the invention herein is concernedare prepared by first loading in the columns a gasless ignitioncomposition followed by one or more increments (in the above mm.example, three increments are used) of manganese delay powder, capped bya single increment of black powder. The gasless ignition compositionusually consists of a formulation of powdered zirconium, ferric oxideand diatomaceous earth and serves as the ignition link between theprimary expelling charge and the manganese delay train. It is selectedfor ease of ignition and to have a burning temperature of sufficienthigh order to insure ignition of the manganese composition. Themanganese delay composition is formulated to burn at a controlled rateto provide proper delay between primary and secondary expelling chargeignition. When the burning surface of last manganese increment in thedelay train reaches the black powder, it ignites the black powder whichfires with suflicient force to ignite the secondary expelling charge(also black powder).

As noted above, the present invention is concerned with a device andmethod for compacting or consolidating the increments in the delay trainin the delay assembly. In prior art methods for accomplishing thisobjective each train in each column has heretofore been compactedindividually and in sequence, often resulting in gross variations inburning rate of the thereby compacted delay train. Attempts have alsobeen made to consolidate both colurnns simultaneously, but results werelargely unsatisfactory due to unequal distribution of the consolidatingloads applied. This occurs because, in practice, each increment in eachcolumn of the assembly is first volumetrically dispensed therein usingsuitable scoops, or measuring cups to pour into the columns, uncompactedmaterial having the loose form of powder or the like, after which theassembly is positioned on a punch press and a consolidating loadimpressed. Thus, it can be seen that prior to consolidating, the loosematerial will often be at different levels and of varying densities,hence attempts to consolidate both columns simultaneously, usuallyresults in unequal force distribution.

It is therefore an object of this invention to provide a dual forcetransmitting punch assembly wherein a pair of delay trains in a delayassembly of a fused projectile and the like are subjected to equalconsolidating loads simultaneously.

It is an additional object of this invention to provide a device of thecharacter referred to wherein free floating punches are employed toconsolidate loose material in a pair of columns in a delay or fuseassembly under equal forces, simultaneously, from a single forceproducing instrument.

A further object of this invention is to provide a device of thecharacter described which is of simple construction, self-compensatingwith respect to both wear and alignment and capable of transmittingequal forces through each of two punches regardless of the relativelevel of the punches.

Other objects and advantages of the present invention will becomeapparent to skilled artisans from a consideration of the followingdescription of a preferred and one additional embodiment thereof,especially when taken in conjunction with the accompanying drawings inwhich:

FIGURE 1 is a pictorial, exploded view of a preferred embodiment of theinvention;

FIGURE 2 is a front elevation of an additional embodiment of theinvention, partly in section;

FIGURE 3 is a side elevation, partially sectioned of the invention ofFIGURE 2;

FIGURE 4 is a side elevation, partially in section, showing theinvention in a punch press prior to consolidating the delay compositionin a delay assembly; and

FIGURE 5 is a sectional view of the front portion of a typical flareprojectile showing the relative position of a delay assembly thereinafter being consolidated by the invention.

Referring now to the drawings, and in particular to FIGURE 1, there isillustrated a preferred embodiment of the invention comprising a punchassembly 10, which includes a hollow housing 11. Housing 11 has athreaded upper portion 12 which is provided for attachment thereof to avertical punch press 13 (FIGURE 4). A pivot pin 14 extends in swivellingrelationship therewith through a pair of opposite walls 15 in housing 11in openings 16 (one only shown in FIGURE 1) therein. Pivot pin 14 alsoextends through a hole 17 in a pivot, or toggle bar 18 being in pressfitted, or non-slipping engagement therewith. Bar 18 is therebyswivelably, or rotatably supported by pin 14 in housing walls 15, beingdimensioned to freely rotate, or swivel about the long axis thereofwithin housing 11. Pivot bar 18 is symmetrically formed with a pair oflobes 19. Lobes 19 have rounded, hardened surfaces, the center of whichare on the transverse (left to right in FIGURE 1) center line of hole17, extremities of which are equidistant from the center thereof. Pin 14can alternatively be fixedly attached in walls 15 and bar 18 swivelledthereon in housing 11.

Housing 11 is closed at its bottom surfaces by a bushing plate 20fastened thereat by a plurality of bolts (one shown in FIGURE 1), andhas a pair of through holes 21 into which is press fitted a pair ofbushings 22, which are provided to support a pair of free floatingpunches 23 therein, and are located equidistantly from the lateral axis(front to rear in FIGURE 1). The term free floating as used hereinrefers to the fact that punches 23 contact bushings 22 so as to befreely movable vertically therewithin. Bushings 22 are therefore made ofhard, smooth surfaced material such as steel or other suitably hardsubstance available. Thus, punches 23 are fitted in bushing 22 underrelatively close tolerances circumferentially, but easily movablevertically therein, thereby avoiding unwanted misalignment problems inuse as will become apparent. Punches 23 are further formed with heads24, which have their top surfaces, in operation, contacting the lower,hardened surfaces of lobes 19 of bar 18.

FIGURES 2 and 3 illustrate another embodiment of the invention wherein amodified pivot or toggle bar 18a is shown. Modified bar 18a is, however,swivelably, or rotatably mounted in housing 11 in the same way as thepreviously described embodiment, on pivot pin 14. In this embodiment,modified toggle bar 18a has bifurcated ends 25 and is provided with apair of transverse holes into which a pair of clevis or dowel pins 26are fixedly inserted. Pins 26 are positioned in the body of bifurcatedbar 18a adjacent each side of pin 14 and are diametrically sized to havetheir lower, circumferential portions extend into bifurcations 25, andtheir centers positioned on the transverse center line of pin 14.Punches 23 extend into the space between bifurcated ends 25 and contactthe exposed, circumferential portions of pins 26, as best seen in FIG-URE 3. I

FIGURE 4 illustrates the punch assembly 10 of the in vention attached topunch press 13 in a position at the beginning of a compacting orconsolidating stroke. Also shown in FIGURE 4 is a delay or fuse assembly27 held in a jig or fixture 28 on the work table 29 of press 13. Delayassembly 27 is positioned on table 29 in inverted position to facilitatefilling columns 30 therein to form a delay train 31 (see also FIGURE 5)with combustible material which is to be consolidated. Delay assembly 27shown also in FIGURE 2 in dotted outline with punches 23 inserted incolumns 30 for alignment therewith; jig, or fixture 28 being omitted forclarity. A flash shield 43 surrounds assembly 10 in FIGURE 4 forprotection of .4 the punch press operator while using the invention who,as indicated in this figure, works and observes from the left.

FIGURE 5 illustrates the position of delay assembly 27 in the forwardend of a flare projectile 32. As shown, delay assembly 27 comprises abody 33 with delay train 31 in columns 30 fully compacted and comprisinga black powder capping 34, three increments of manganese delaycomposition 35 and a single increment of a gasless powder composition36. Forward of delay assembly 27 is a primary expelling charge 37composed of a fast burning composition which abuts body 33. A mechanicaltiming fuse 38 forwardly abuts charge 37 in the nose of projectile 32.

Delay assembly 27 is threadedly engaged in the forward end of an innerhousing 39 of projectile 32 and surrounds a secondary expelling charge40 composed of black powder which abuts the aft end of assembly 27.Charge 40 may be encased in a silk bag or other cover (not shown) inpractice, which is penetrable by the igniting force of black powderincrement 34 of delay 27.

Housing 39 is slidably positioned in projectile 32 and encloses a casing41 containing the illuminating charge or candle 42 of flare 32, whichabuts the aft end of expelling charge 40.

In operation of the invention a delay assembly 27 is positioned on table29 of press 13 in inverted position, i.e., with the aft end, as seen inFIGURE 5, upward. Assembly 27 is held in position in jig 28 between analignment bar 43 and a hold-down bar 44 thereby insuring that punches 23are in vertical alignment with columns 30 in delay assembly 27.Alignment bar 43 includes a pair of vertical press fitting pins (notshown) which extend therefrom into the now inverted forward openings ofcolumns 30 to control the depth of the forward face of the gaslessignition powder 36. As indicated hereinabove the material making updelay trains 31 are volumetrically dispensed into train holes or columns30 by means of any suitable funnel, scoop or dispensing ladle (notshown). Following addition of gasless ignition powder 36 a firstincrement of manganese delay composition 35 is dispensed into columns 30and a consolidation load on the order of 1,000 lbs. is impressed on thesurface of composition 35 in each column 30 by press 13 through assembly10.

As indicated elsewhere herein, the inventions unique advantages andusefulness lies primarily in the accomplishment thereby ofsimultaneously consolidating the material contained in both columns 30.As stated, the material is volumetrically dispensed, or loaded thereinand may, prior to consolidation be at different levels. With theinvention herein the consolidation force supplied by press 13 istransmitted to the surfaces of the material in columns 30 in equalporlions since free floating punches 23 will seek their own levels andwill come to rest with their lower ends on the surface of material to becompacted. As force is applied, toggle bar 18 (or 18a) will swivel orrotate about pin 14 and the force produced by press 13 will be dividedthereby-half being transmitted to each punch 23.

Similarly as each manganese increment 35 is placed or poured intocolumns 30, consolidation is effected in the same manner. The finalblack powder increment, or capping 34 is also compacted in the same way,after first trimming, or cutting back the excess manganese increment 35to the desired length.

It has been shown through actual test that improper consolidation of thecombustible material in a delay or fuse assembly is at the base of mostproblems in the art of artillery delivery of flares and other suchprojectiles over preselected targets. The primary defect in priorattempts to load delay assemblies has been their failure to meet adesired, or required burning time, which is usually attributed toimproper consolidation either because of poor alignment or improperdistribution of compacting loads. Another defect resulting from improperconsolidation is failure of the delay train to sustain ignition, i.e.,

failure of gasless ignition powder 36 to maintain burning until itsburning surfaces reaches black powder capping 34. Thus, theconsolidating step herein described and the novel means foraccomplishing it is the single most important part of projectiles of thegeneral type wherein a predetermined delay between events in a sequenceis required. Such a device is exemplified in FIGURE 5 wherein the headend of projectile 32 is illustrated.

Projectile 32 is designed to be fired fro-m a 155 mm. howitzer, on atrajectory which places it over a target area at a prespecifiedaltitude, after which a fully opened parachute descent of anilluminating flare is effected. In actual firing conditions mechanicaltiming fuse 38 is set for the desired fuse actuation time. Projectile 32upon leaving the barrel of the howitzer is undergoing rotation,therefore the timer of fuse 38 is initiated in response to rotation.Upon fuse actuation at the end of a predetermined time, primaryexpelling charge 37 fires, driving housing 39, together with delayassembly 27 and cannister 41 and its contents 42 afterwardly out of thebody of projectile 32. This explosion ejects a drogue parachute (notshown) from the aft end of projectile 32 which provides initialdeceleration of housing 39 and its contents. At the same time, delaytrains 31 in columns 30 of delay assembly 27 are ignited. Delay trains31 which have been consolidated by use of punch assembly 10, theinvention described and claimed herein, burn for a period ofapproximately 7.5 seconds, during which time ejected cannister 41,candle 42, housing 39 and assembly 27 are being decelerated by thedrogue parachute, above mentioned. Also during this time it is usual toprovide some means such as extendible braking fins or the like (also notshown) to halt rotation of the spinning, nowejected, components.

At the end of the delay period, the burning surface of final incrementreaches and ignites black powder capping at, which, in turn, ignitessecondary expelling charge 40. Firing of expelling charge 40 causesejection of cannister 41 from housing 39 and also ejects a main flareparachute (not shown) usually packed in the aft end of projectile 32 andattached to cannister 41. Simultaneously illuminant, or flare candle 4-2is ignited and provides illumination during descent thereof by the mainparachute over the traget area.

As is apparent from the foregoing, delay assembly 27 performs a veryimportant function in projectiles of the type above generally referredto. Therefore, burning delay train 31 must be reliable, and since twosuch trains are most frequently used to increase reliability, they musthave as many of the same characteristics as possible.

By use of the invention hereinabove described and claimed below, thishas now become realizable to an unprecedented degree, since therecognized main source of difliculty, improper consolidation of thecombustible material, has been practically eliminated.

What is claimed is:

1. A punch assembly adaptable for use in a punch press to consolidatecombustible solid materials in powder train delay and fuse devices andthe like comprising:

a housing having walls defining a chamber, a bushing plate having a pairof holes extending therethrough, said plate removably attached to saidhousing and forming a bottom for said chamber;

a hollow bushing in each of said holes, said bushings being press fittherein;

a swivelable pivot bar in said housing;

pivot means in said chamber terminating in opposite walls of saidhousing for supporting said pivot bar; and

a pair of elongated punches contacting said pivot bar in said housingand extendable through said bushings in said holes for consolidatingsaid combustible material in said delay and fuse devices under apreselected load produced by said punch press.

2. The punch assembly of claim 1 wherein said pivot means is acylindrical pin passing through said pivot bar in press fittedengagement therewith having its ends extending into said chamberopposite walls in a slip fit for swivelling said pivot bar.

3. The punch assembly of claim 1 wherein said pivot :bar includes a pairof press fitted dowel pins, the outer periphery of which contact saidpunches in force transmitting engagement therewith in said housing.

4. The punch assembly of claim 1 wherein said pivot bar comprises a bodyhaving a pair of downwardly extending, rounded surfaces, each of saidsurfaces contacting one of said punches in force transmitting engagementtherewith in said housing.

BENJAMIN A. BORCHELT, Primary Examiner STEPHEN C. BENTLEY, AssistantExaminer US. Cl. X.R. 86-30

